General marine vessels, including various boats and ships, are subjected to rolling and pitching when navigating the sea with surges and strong wind. At this point, the antennas fixedly mounted on the marine vessels will sway along with the rolling and pitching marine vessels to cause continuous changes in the range of wireless signal transmission via the antennas. This condition has adverse influence on the quality of wireless signal transmission among neighboring vessels via the antennas, and results in narrowed wireless signal range as well as unstable signal transmission quality, errors in information generated by on-board communication apparatus and other related precision instruments. In worse conditions, the on-board communication apparatus and precision instruments might become useless under the server navigation condition on the sea. Besides, the antennas on the marine vessels are frequently exposed to sunlight, rainwater, and corrosion by sea wind to result in short circuit or other safety-related problems of the apparatus and devices connected to the antennas. In the event the apparatus and devices connected to the antennas are damaged, a large amount of labor, time and money is required to repair them.